1. Technical Field
The present invention relates to a virtual image display apparatus that presents a viewer with video images in the form of virtual images, and particularly to a virtual image display apparatus suitable for a head-mounted display worn around the head of the viewer.
2. Related Art
A variety of optical systems incorporated in a virtual image display apparatus, such as a head-mounted display (hereinafter also referred to as HMD) worn around the head of a viewer, have been proposed (see JP-A-2011-2753 and JP-A-2010-145859, for example).
A virtual image display apparatus, such as an HMD, is desired to achieve further size and weight reduction and an increase in the angle of view without degradation in image quality. Further, when the entire view of the viewer is covered and only video image light is visible to the viewer, the viewer is unable to know what is going on outside and hence feels anxious. Instead, when the viewer is allowed to see the outside superimposed with video images, a new application, such as virtual reality, is created. It is therefore desired to develop a display that does not obstruct the outside view but displays it with video image light superimposed thereon. Further, to improve comfort and appearance of the viewer who wears the virtual image display apparatus, it is typically desirable that the shape of the apparatus is similar to that of glasses.
In view of the circumstances described above, it is conceivable to configure a virtual image display apparatus based, for example, on a light guide section so disposed in front of the viewer's eyes that see-through observation is achieved and guide video image light from an image display device to the viewer's eyes via the see-through-type light guide section. In a virtual image display apparatus of this type, in which it is necessary to support the light guide section in front of the eyes, for example, a pair of image display units each including an image light generator and a light guide plate are fixed to a connection member, which is fixed to the rear of a frame similar to a frame of glasses (see JP-A-2011-2753).
In the virtual image display apparatus described, for example, in JP-A-2011-2753, however, since the connection member is provided separately from the frame and supports the image display units, the structure is complicated. Further, increasing the strength at which the connection member supports the image display units tends to increase the weight of the apparatus, whereas reducing the weight of the connection member and other components tends to lower the strength at which the image display units are supported.